1642834 - Add a comment to RenderCompositorANGLE::RequestFullRender()

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, task)

Description

[Sotaro Ikeda [:sotaro]]

Bug 1637497 Comment 27 requests comments about why full render is necessary when DWM is disabled.

Comment 1

[Sotaro Ikeda [:sotaro]]

When DWM is disabled, each window does not have own back buffer. They share a buffer and WM_PAINT triggers necessary re-paint. On compositor, the followings handles it.

• nsWindow::OnPaint()
• ClientLayerManager::SendInvalidRegion()
  CompositorBridgeParent::RecvNotifyRegionInvalidated()

And WebRender does not support invalid region yet. WebRenderLayerManager::SendInvalidRegion()

Instead WebRenderBridgeParent::RecvInvalidateRenderedFrame() is used for now.

The following article explains about non-dwm paint.

In all versions of Windows, up until Windows XP, applications were asked by Windows to paint their visible region, and they would paint directly to the buffer that was to be displayed by the video card.

• https://www.vistaforums.com/threads/great-article-under-the-hood-of-the-desktop-window-manager.1603/

Comment 2

[Sotaro Ikeda [:sotaro]]

(In reply to Sotaro Ikeda [:sotaro] from comment #1)

And WebRender does not support invalid region yet. WebRenderLayerManager::SendInvalidRegion()

Instead WebRenderBridgeParent::RecvInvalidateRenderedFrame() is used for now.

There is a choice to call WebRenderBridgeChild::SendInvalidateRenderedFrame() in WebRenderLayerManager::SendInvalidRegion().

Comment 3

[Sotaro Ikeda [:sotaro]]

There is a choice to call WebRenderBridgeChild::SendInvalidateRenderedFrame() in WebRenderLayerManager::SendInvalidRegion().

Bug 1642839 is created for it.

Comment 4

[Sotaro Ikeda [:sotaro]]

Attachment: Bug 1642834 - Add a comment to RenderCompositorANGLE::RequestFullRender()

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e69116203259
Add a comment to RenderCompositorANGLE::RequestFullRender() r=jrmuizel

Comment 6

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/e69116203259